readFITSbintable {FITSio}R Documentation

Read a FITS binary table

Description

Read a FITS binary table from an open connection to a FITS file.

Usage

readFITSbintable(zz, hdr)

Arguments

zz file handle; see Example.
hdr vector of header information from readFITSheader.

Details

readFITSbintable reads the data from the binary table part of a FITS Header and Data Unit containing binary table data. The header must be read first by readFITSheader to provide the variable hdr. Binary tables are multi-column files with one or more rows. Each column has an individual data type and number of entries per cell (i.e., a cell may contain a scalar or vector).

Binary table bit, complex, and array descriptor data types are not implemented in this release due to a lack of examples for testing.

Value

col Data from each column, either a vector or an array.
hdr Vector with parsed header.
colNames Vector of column names, TTYPEn FITS variable.
colUnits Vector of column units, TUNITn FITS variable.
TNULLn Vector of undefined value definitions, FITS variable.
TSCALn Vector of multipliers for scaling, FITS variable.
TZEROn Vector of zeros for scaling, FITS variable.
TDISPn Vector of format information, FITS variable.

Note

Graphical FITS viewers such as fv (http://heasarc.gsfc.nasa.gov/ftools/fv/) and SAOImage DS9 (http://hea-www.harvard.edu/RD/ds9/) have excellent facilities for displaying FITS data, headers, and file structure. Having one or more graphical viewers available will prove extremely useful for working with FITS files, even when the data are read into R for further processing. fv and SAOImage DS9 are in active devlopement with support for unix, Windows, and Mac OS-X operating systems, and are available at no cost.

Author(s)

Andrew Harris

References

Hanisch et al., Astron. Astrophys. 376, 359-380 (2001)

http://fits.gsfc.nasa.gov/

See Also

readFITS, readFITSheader, readFITSarray, file

Examples

require("FITSio")

## Either download example file from
## <http://fits.gsfc.nasa.gov/fits_samples.html>
## and use
## Not run: filename <- "IUElwp25637mxlo.fits"
## or, for local example use
filename <- system.file("fitsExamples", "IUElwp25637mxlo.fits",
                        package = "FITSio")  

## Open file, read header and table, close file.
zz <- file(description = filename, open = "rb")
hdr <- readFITSheader(zz) # read primary header
hdr <- readFITSheader(zz) # read extension header
D <- readFITSbintable(zz, hdr)
close(zz)

## Look at contents 
summary(D)
D$hdr[which(D$hdr=="BITPIX")+1]   # BITPIX value from header
D$colNames
plot(D$col[[5]], ylab = "Value", main = D$colNames[5], type = "l")


[Package FITSio version 1.0-2 Index]